On energy harvesting from ambient vibrations through an oscillating pendulum system fixed to a suspended platform
In recent years, the importance of the energy harvesting concept has been growing gradually and, therefore, is related to various applications. Many of these applications are related to devices that usually try exploiting thermal, kinetic, vibrational, and electromagnetic energy. Energy extraction from a base excited pendulum has been studied by several authors, and the dynamic behavior of the damped vertically excited pendulum has been studied extensively [1-4]. The optimization of harvested energy by a parametrically excited pendulum was considered using the control of damping and variations of the excitation source . A proposed approach  is to extract energy by converting vertical oscillations into rotary motion using a pendulum. Another described proposed approach  is to use a system to generate compressed air using a pendulum oscillation energy converter. The principle of a pendulum oscillation energy converter was introduced , and the designs of the dual-medium pressurizer and the dual-stroke hydraulic system are emphasized. An experimental apparatus has been built to simulate the production of energy from pendulum oscillations . Pendulum systems have also been used as a passive control of electro-mechanical systems , and for energy harvesting [6-8]. The results for the latter application showed a greater uptake of energy for the cases where the behavior is chaotic. In this paper, the inverted pendulum dynamics is analyzed regarding its ability to generate energy through the ocean wave oscillations. To generate energy through the movements of the pendulum, two pneumatic pistons are introduced in the system with the goal of storing compressed air to generate electricity. This strategy is similar to the one proposed by . In order to obtain the optimal compressed air generation [5, 10], the system parameters were analyzed via numerical simulations.